from tkinter import filedialog, messagebox

import customtkinter as ctk
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg
from matplotlib.figure import Figure

from app.ui.base_frame import BaseAppFrame


class ReportsFrame(BaseAppFrame):
    """Screen with text reports and charts."""

    def __init__(self, master, refresh_callback) -> None:
        super().__init__(master, refresh_callback)
        self.last_report_text = ""
        self.grid_columnconfigure((0, 1), weight=1)
        self.grid_rowconfigure(1, weight=1)
        self._build_header()
        self._build_left_panel()
        self._build_right_panel()

    def _build_header(self) -> None:
        header = ctk.CTkFrame(self, fg_color="transparent")
        header.grid(row=0, column=0, columnspan=2, sticky="ew", padx=8, pady=(8, 12))
        header.grid_columnconfigure(0, weight=1)

        self.title_label(header, "Аналитика и отчёты").grid(row=0, column=0, sticky="w")
        self.subtitle_label(
            header,
            "Текстовая сводка, диаграмма расходов и экспорт отчёта.",
        ).grid(row=1, column=0, sticky="w", pady=(4, 0))

        self.export_button = self.primary_button(
            header,
            "Сохранить отчёт в TXT",
            lambda: self.run_safe(self.export_report, self.export_button),
        )
        self.export_button.grid(row=0, column=1, rowspan=2, padx=(12, 0))

    def _build_left_panel(self) -> None:
        left = ctk.CTkFrame(self, corner_radius=20)
        left.grid(row=1, column=0, sticky="nsew", padx=(8, 12), pady=8)
        left.grid_rowconfigure(1, weight=1)
        left.grid_columnconfigure(0, weight=1)

        self.section_label(left, "Отчёт за текущий месяц").grid(
            row=0,
            column=0,
            sticky="w",
            padx=18,
            pady=(18, 8),
        )
        self.report_box = ctk.CTkTextbox(left)
        self.report_box.grid(row=1, column=0, sticky="nsew", padx=18, pady=(0, 18))

    def _build_right_panel(self) -> None:
        right = ctk.CTkFrame(self, corner_radius=20)
        right.grid(row=1, column=1, sticky="nsew", padx=(0, 8), pady=8)
        right.grid_rowconfigure(1, weight=1)
        right.grid_columnconfigure(0, weight=1)

        self.section_label(right, "Структура расходов").grid(
            row=0,
            column=0,
            sticky="w",
            padx=18,
            pady=(18, 8),
        )
        self.chart_container = ctk.CTkFrame(right, fg_color="transparent")
        self.chart_container.grid(row=1, column=0, sticky="nsew", padx=18, pady=(0, 18))

        self.figure = Figure(figsize=(5, 4), dpi=100)
        self.canvas = FigureCanvasTkAgg(self.figure, master=self.chart_container)
        self.canvas.get_tk_widget().pack(fill="both", expand=True)

    def refresh_data(self) -> None:
        self.last_report_text = self.service.build_report_text()
        self.report_box.delete("1.0", "end")
        self.report_box.insert("1.0", self.last_report_text)
        self._draw_chart()

    def _draw_chart(self) -> None:
        data = self.service.report_data()
        rows = data["categories"]
        self.figure.clear()
        axis = self.figure.add_subplot(111)
        axis.set_title("Расходы по категориям")
        if rows:
            labels = [row["name"] for row in rows]
            values = [row["total"] for row in rows]
            axis.pie(values, labels=labels, autopct="%1.1f%%")
        else:
            axis.text(0.5, 0.5, "Нет данных для диаграммы", ha="center", va="center")
            axis.axis("off")
        self.canvas.draw()

    def export_report(self) -> None:
        if not self.last_report_text:
            self.refresh_data()
        file_path = filedialog.asksaveasfilename(
            defaultextension=".txt",
            filetypes=[("Text files", "*.txt")],
            title="Сохранить отчёт",
        )
        if not file_path:
            return
        with open(file_path, "w", encoding="utf-8") as file:
            file.write(self.last_report_text)
        messagebox.showinfo("Готово", "Отчёт сохранён.")